Re: [PATCH 2/4] soc: Mediatek: Add SCPSYS power domain driver

From: Kevin Hilman
Date: Tue May 26 2015 - 18:35:24 EST


Sascha Hauer <s.hauer@xxxxxxxxxxxxxx> writes:

> This adds a power domain driver for the Mediatek SCPSYS unit.
>
> The System Control Processor System (SCPSYS) has several power
> management related tasks in the system. The tasks include thermal
> measurement, dynamic voltage frequency scaling (DVFS), interrupt
> filter and lowlevel sleep control. The System Power Manager (SPM)
> inside the SCPSYS is for the MTCMOS power domain control.
>
> For now this driver only adds power domain support, the more
> advanced features are not yet supported. The driver implements
> the generic PM domain device tree bindings, the first user will
> most likely be the Mediatek AFE audio driver.
>
> Signed-off-by: Sascha Hauer <s.hauer@xxxxxxxxxxxxxx>
> ---
> drivers/soc/mediatek/Kconfig | 6 +
> drivers/soc/mediatek/Makefile | 1 +
> drivers/soc/mediatek/mtk-scpsys.c | 345 +++++++++++++++++++++++++++++++
> include/dt-bindings/power/mt8173-power.h | 15 ++
> 4 files changed, 367 insertions(+)
> create mode 100644 drivers/soc/mediatek/mtk-scpsys.c
> create mode 100644 include/dt-bindings/power/mt8173-power.h
>
> diff --git a/drivers/soc/mediatek/Kconfig b/drivers/soc/mediatek/Kconfig
> index bcdb22d..1d34819 100644
> --- a/drivers/soc/mediatek/Kconfig
> +++ b/drivers/soc/mediatek/Kconfig
> @@ -9,3 +9,9 @@ config MTK_PMIC_WRAP
> Say yes here to add support for MediaTek PMIC Wrapper found
> on different MediaTek SoCs. The PMIC wrapper is a proprietary
> hardware to connect the PMIC.
> +
> +config MTK_SCPSYS
> + tristate "MediaTek SCPSYS Support"

depends on ARCH_MEDIATEK ?

> + help
> + Say yes here to add support for the MediaTek SCPSYS power domain
> + driver.

[...]

> +static int scpsys_probe(struct platform_device *pdev)
> +{
> + struct genpd_onecell_data *pd_data;
> + struct resource *res;
> + int i;
> + struct scp *scp;
> +
> + scp = devm_kzalloc(&pdev->dev, sizeof(*scp), GFP_KERNEL);
> + if (!scp)
> + return -ENOMEM;
> +
> + scp->dev = &pdev->dev;
> +
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + scp->base = devm_ioremap_resource(&pdev->dev, res);
> + if (IS_ERR(scp->base))
> + return PTR_ERR(scp->base);
> +
> + pd_data = &scp->pd_data;
> +
> + pd_data->domains = scp->pmd;
> + pd_data->num_domains = NUM_DOMAINS;
> +
> + for (i = 0; i < NUM_DOMAINS; i++) {
> + struct scp_domain *scpd = &scp->domains[i];
> + struct generic_pm_domain *pmd = &scpd->pmd;
> +
> + scp->pmd[i] = pmd;
> + scpd->data = &scp_domain_data[i];
> + scpd->scp = scp;
> +
> + pmd->name = scp_domain_data[i].name;
> + pmd->power_off = scpsys_power_off;
> + pmd->power_on = scpsys_power_on;
> + pmd->power_off_latency_ns = 20000;
> + pmd->power_on_latency_ns = 20000;

I think I mentioned this before... are these numbers really identical
for all domains? I suggest you make these each a field in the domain
data so they can be different for each domain, and eventually come from
DT data.

> + pd_data->domains[i] = pmd;
> + pm_genpd_init(pmd, NULL, 1);
> +
> + /*
> + * If PM is disabled turn on all domains by default so that
> + * consumers can work.
> + */
> + if (!IS_ENABLED(CONFIG_PM))
> + pmd->power_on(pmd);
> + }
> +
> + return of_genpd_add_provider_onecell(pdev->dev.of_node, pd_data);
> +}

Kevin
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